The groundbreaking discovery of a new species of early hominid in South Africa’s Cradle of Humankind has shed new light on what we know about the species that roamed the Earth before early man.

Fossils of the new species, which has been named Homo naledi, were discovered during National Geographic’s "Rising Star" exploration at one of the world’s richest hominid fossil sites in the Cradle of Humankind World Heritage Site, about an hour outside of Johannesburg.

“Naledi” is Setswana for “star”, and the name’s been chosen as a tribute to the Dinaledi cave system where scientists made the find in September 2013.

More remarkable, Berger says, is that the fossils revealed the newest species to the genus, Homo.

“Homo naledi represents an extraordinary discovery because it’s something we never expected: small brains, a primitive and evolved body something that I think no one expected to exist in the fossil record,” Berger says.

Berger says the find and the expedition, which unearthed more than a thousand individual remains is significant for South Africa.

“The science of paleoanthropology actually began in South Africa with the discovery of the Taung Child back in 1924, but after the 1950s, the interests of scientists moved to East Africa, where great discoveries were made and that was probably true, right up until the early 21st century.

“Then discoveries began to be made in southern Africa again, surprisingly, right in the areas where we’d been looking. We thought there was nothing left to find.

“Now, particularly over the past six years, we’ve realised that not only is this area practically unexplored, but it holds some of the best and richest fossil deposits on the planet,” he says.

The Rising Star expedition was in itself a remarkable one. The extraordinary chamber was found about 30m underground, and was only accessible through an extremely narrow chute.

Getting access through the small opening was so difficult that Berger had to co-opt a team of “underground astronauts” for the task - scientists who didn’t just have PhDs and experience in working in caves, but who were also skinny enough to scale down the narrow chute to get to the fossils.

One of the first scientists to enter the cave was post-doctoral research fellow at Wits, Marina Elliot.

“Just before you reach the chamber where the fossils are, it’s a very tight squeeze,” she said.

“It’s kind of a birthing into this chamber. You look around, you’re wearing a headlamp. Everywhere your light shone, you could see there were bone fragments. It was really thrilling to realise how much material was there.”